But how will they make it to the chapel at that future wedding? (Yes, they do get married.) After all, Barney proposed to Quinn (Becki Newton) in present day on the finale. Thomas answers our burning questions below. Plus: He tells us what's next for Ted (Josh Radnor) now that he's driving off with "the one who got away" Victoria (Ashley Williams) — who ditched her fiancé Klaus on their wedding day for him — and how they came up with the "coolest middle name" for Lily and Marshall's son, Marvin Wait For It.

So it had to be Robin, right? Craig Thomas: Right? It had to be Robin. That's how we felt. When they were together in Season 5 and we broke them up ... it was very divisive. Some fans were like, "Great! Barney's back to being Barney. I don't want to see him in a relationship." But there were a lot of people [who were] like, "Boy, I feel really unfinished about Barney and Robin." We knew at the time that we had all this other Barney and Robin saga up our sleeve. We were at that point planning out what Seasons 6 and 7 would be. We knew that they would have this momentary flirtation with rekindling in Season 7 that we just did, but Robin chose Kevin (Kal Penn). Barney was heartbroken and I think in that moment, people were like, "Aw! Bros, what are you doing to us?!" ... Of course, in the back of our heads, whenever we heard that feedback, we were thinking, "Just wait! We're gonna get to it." But yeah, it had to be her. They're a special couple.Not only because of her history with Barney, but Ted — otherwise why start this story by telling his kids how he met Robin?Thomas: Yeah, it comes back around. It's like at that wedding, he fully lets [Robin] go and can then meet the love of his life. ... There's also some stuff to play with Ted dealing with [them getting married]. Robin's a very incendiary presence in this group's life. Robin's that girl who you can't fully put out of your mind. As we saw this season, Ted wasn't quite over her, and it always felt like something was unfinished with Barney and Robin.When did you and Carter [Bays] decide that Barney and Robin will get married?Thomas: We decided literally years ago. As we were breaking them up, we knew there would be a rekindling and that wouldn't be the real deal ... and we would reveal them to be the groom [in the Season 6 finale] and bride now. ... Season 8 is gonna be filling in the steps between Point A and Point B. We know they do get married, but there are a lot of steps between Point A and Point B. In the last few minutes of this finale, it definitely seems like Barney is marrying Quinn. They get engaged, he has this enormous, elaborate engagement planned involving a magic trick. It's really romantic and sweet, and it plays like an ending. It had a finality to it, but the whole episode is about misdirection and magic, and the one last trick up our sleeve was revealing that Robin's the bride.We tell stories in funky ways. There's a lot of fun with structure. It's a little weird and a little counterintuitive to show people an ending of sorts and fill in how we got there, but there are so many mysteries and runners and different questions to answer in the show that we like the idea of answering something big about this wedding day because we know Barney's future wedding day is the day Ted will meet the mother. One guess that's been around even before the groom and bride reveals is that Ted meets Barney's half-sister at the wedding and marries her. Now that we know bride and groom, that might become the main theory.Thomas: It's cool seeing what HIMYM fans come up with. Obviously I'm terrible and I can't say much about the mother, but we will get more clues about her in Season 8. ... We were kind of light on it this year. But now that we've established these two huge facts about this wedding day that's "a little ways down the road," there's a built-in mystery and we can show you the endgame.Ted's driving off with Victoria, but we know that she's not the mother. Thomas: That's why it's really fun with storytelling time! [Laughs] But it felt very relatable to us. I think everybody in their love life has had someone they felt they screwed it up with or that person could've been the one or if circumstances had been different, maybe that was the one. That's how Ted feels about Victoria. He screwed that up in Season 1. ... Ted doesn't know this in 2012 — he still thinks Victoria could be the mother of his children — but we, the audience, and astute HIMYM fans know more than him thanks to Bob Saget. We love Victoria representing the door that's still open a crack in Ted's mind. He has to see what's behind that door and eventually close it to be able to meet the mother. As we head toward the end of the series, it's one of the last things Ted has to do.

Without knowing if Season 8 is the last season, how much can you plan out? Where will we pick up in the premiere? Will we see the wedding again?Thomas: I can't say when we'll see the wedding again, but we have a bunch of the big moments of Season 8 plotted out. We're waiting on negotiations with actors and all that to see if this is it. That makes it a little tricky. It's like we'll be fixing the car as we're driving it. It's the point where business and art meet. But hopefully anyone who sees the finale can attest to the fact that there is a lot to explore from the finale.Our premiere picks up right on the same day in May that most of the finale takes place on. It'll be our first episode where we tell a whole story that's still back in May because there's so much stuff going on. ... One of the exciting incidents is Ted's story. Ted got left at the altar by Stella (Sarah Chalke), so we pick up on Ted and Victoria driving off into the sunset and Ted casually asks Victoria, "Hey, what did you say in that note that you left for Klaus?" And she sort of awkwardly says, "I didn't leave a note." Ted, being Ted Mosby, who has a very heightened sense of what is right, says, "You gotta leave a note! I got left at the altar, but at least I got a note! The note is very helpful!" So he turns the car around and they're gonna leave a note for poor, abandoned Klaus. The episode sort of sparks from Ted's decision to turn the car around. Ultimately, we'll see if that's a good idea. That's such a Ted Mosby decision. We did want to tend to the fact that we did see him on the other end of this equation of a runaway bride. Episode 801 will be all on that day.Will Barney and Quinn ever make it to Hawaii?Thomas: I don't want to say exactly. But you haven't seen the last of Quinn. I've heard Becki Newton has booked another gig. [Laughs] ... But we're the boss, so we can use her on HIMYM too. We have to show what happens with Barney and Quinn, how he gets through that, how does he ever get to a place where he's ready to consider something serious again, and how does he get back with Robin. That's a big emotional journey; that's not two episodes.Everyone noticed in the 2015 flash-forward in "Trilogy Time" that we can't see Barney's left ring finger.Thomas: Very intentionally done that way. One of those little moments where you realize what a good actor Neil Patrick Harris is because he can somehow make hiding his left hand seem perfectly natural. We don't want to give away too much. Remember: Barney and Robin's wedding won't be smooth, but they will get married.Robin and Ted finally made up. Are they good going forward?Thomas: Yeah. Ultimately, there's nothing like your friends having a baby to bring you together. It felt natural. In the finale, Robin launches into this cheerleader for Ted. She wants Ted to be happy. It's hard seeing a friend be down, especially if you were the one who did it by not saying "I love you" back. ... Robin's drive in the finale is, "I want to encourage Ted to go after someone who could've been the one." She thinks, "It was never gonna be me. We don't quite want the same things. He needs to get over being hung up on me and go back to someone who might have been the answer." Other than Robin, the only other possibility of who could've been the love of Ted's life is Victoria. A lot of friends, people I know, have someone serious who they think they will end up with, and it just isn't. They need to go back and find that out again.

Is there any romance in store for Robin other than Barney or is she solely focused on her career?Thomas: She's gonna have a love interest other than Barney. We can't just break up Barney and Quinn and slap them together. There's another guy next season. She's moving on with her life. Barney's engaged. As far as she's concerned — when she says "I'm happy for you" in the finale — she believes she means that. That really was supposed to play like Barney and Robin closing the door. Barney makes a joke, "Oh, it's our last chance to run away together," and it's a bittersweet scene. I've seen it 5,000 times, so I hope it plays real! It's two friends agreeing to be friends, agreeing to be happy for each other. Then lo and behold, Robin's in a wedding dress! We can't forget about Lily (Alyson Hannigan)and Marshall (Jason Segel)and Marvin Wait For It — probably one of the greatest middle names ever.Thomas: That's the best middle name of all time, right? [Laughs] I think any name that has a built-in dramatic pause is the coolest name ever. The funny thing is, we came up with that and the obvious reaction for Marshall and Lily to have is, "That's stupid, Barney" and not do it. Somehow, the more we put the story together, we said, "It's really cool." Middle names are kind of bogus. How often do you tell someone your middle name? Mine's David. Who cares? And you'd think Lily is gonna shoot it down, but she goes, "That's the coolest middle name of all time! Let's do it!" There was something really satisfying about allowing ourselves to do that. And we love Marshall and Lily. Marshall and Lily are the coolest couple ever. They're my favorite TV couple ever. Obviously I'm a little biased, but I love them for going with that. I don't know if people will think "Oh, that's insane! I don't buy it." But middle names aren't that useful and why not? You can always go by the "W" initial. He could change it, but why would you want to when that's your middle name?I love that they brought him to the bar.Thomas: Yeah. But they were horrified with themselves! Their huge life question in Season 8 is "How the hell do we keep drinking at a bar with a baby?" [Laughs] We're gonna show how that's possible. A lot of people are like, "Oh, a kid! You're jumping the shark. You're gonna be so hemmed in now." We're gonna see them find support and help and they're gonna find it in an unlikely place. They'll have their hands full, figuring out the hardest job in the world. How far into the season can you break before you absolutely need to know if it's the last season?Thomas: This is the most obvious answer of all time, but it will be better to know earlier. [Laughs] Right now, there's so much to pick up on the finale that we're full for the first batch [of the season]. We're OK for now, but the sooner we know the better because we like to plants lots of seeds and payoffs. When it's the last season, we want to announce it from the rooftop and say, "Hey, there are 24 more episodes left. They're awesome and you gotta watch it!" If it's the last season, you'll know it's a big momentous season from the first episode. There is a definite plan of how we want to begin the last season, as kind of a "gasp!" moment within that episode. So yeah, we need to figure it out pretty soon.You plotted out the Season 6 and 7 finales ahead of time. Did you do that with 8?Thomas: There's a Plan A and a Plan B, and we just need to figure out which it is. It's frustrating, but there's enough stuff to tell either way. It will work with either plan, but I'm definitely eager to find out. If you hear anything, let me know!What did you think of the How I Met Your Mother finale?